Smaato, a San Francisco-based mobile ad tech company, has been acquired by Chinese marketing firm Spearhead for US$148 million.

Smaato is a mobile supply-side platform that allows mobile developers and publishers to connect their advertising inventory to multiple ad exchanges and demand-side platforms in order to monetise their apps.

The company also offers a mobile ad server, a real-time bidding ad exchange, and an ad network mediation platform.

Spearhead says the acquisition — which is being facilitated by an M&A fund invested by one of its subsidiaries — will help the company expand globally.

In addition, it will allow Smaato to enter China with an established Chinese partner, giving it access to many of the 1.3 billion mobile users in the country.

While Smaato is based in San Francisco, the company was founded in Germany, so in some respects this represents the second recent ad tech exit worth more than US$100 million in recent months. The other was France-based video ad tech company StickyAds, which was acquired by Comcast for more than US$100 million in May.

The most high-profile recent deal was Opera Mediaworks being acquired by a conglomerate of Chinese companies for US$1.2 billion in February. NativeX was acquired by Mobvisa in the same month for just under US$25 million.